1. Field of the Invention
The present invention relates to a contact-type magnetic head used in a magnetic disk apparatus for storing and reproducing data, and in particular, the present invention relates to a single-pole, contact-type thin-film magnetic head for perpendicular reading and writing.
2. Description of the Related Art
Recently, increasing demands have been made for magnetic disk apparatuses which satisfy the requirements of compact size, thinness, low price, and low energy consumption. To satisfy these demands, contact-type thin-film magnetic heads have been developed. Contact-type magnetic heads are intended to normally contact the magnetic disk with a sliding engagement. Contact-type magnetic heads can be fabricated by the use of thin-film forming techniques so that they are very small and very light.
U.S. Pat. No. 5,041,932, for example, discloses such a small thin-film magnetic head. In this prior art, a plurality of thin-film magnetic heads are fabricated on a planar substrate such as a silicon wafer. Each of the magnetic heads has a base structure, a coil, and a pole magnetically coupled with the coil for reading and writing data on the magnetic recording medium. The coil is helically formed around a core, the coil and the core being formed within the base structure. The pole is formed on the side surface of the base structure and connected to the core. A return yoke is also arranged in the base structure near the bottom surface thereof to receive the magnetic flux emitting from the pole.
In addition, a contact pad is arranged on the bottom surface of the base structure for sliding engagement with the magnetic disk, the pole extending from the side surface of the base structure to the side surface of the contact pad. The base structure is long compared to the length of the actual magnetic head, including the coil and the pole, so that the elongated base portion serves as a flexible support member for mounting the magnetic head onto an actuator of the magnetic disk apparatus. In use, the contact pad is urged against the magnetic disk by a weak spring force from the elongated base portion (flexible support member portion).
In this type of magnetic heads, it is preferable that the flexible support member portion has a spring modulus ranging from 100 to 500 mg/mm. To provide this spring modulus, a typical entire magnetic head has approximately the following dimensions.
______________________________________ L = 5-12 mm W = 300-600 .mu.m t = 30-50 .mu.m ______________________________________
where, L is the length of the entire base portion, W is the width of the base portion, and t is the thickness of the base portion.
In the fabrication of the thin-film magnetic head, a plurality of magnetic heads are simultaneously fabricated on one substrate such as a silicon wafer. If a substrate having a diameter of 3 inches is used, it is possible to lay out 280 magnetic heads (70 rows.times.4 columns) on the substrate. However, it is desired to obtain more magnetic heads from one substrate to realize a cost reduction, since the larger the number of magnetic heads obtained from one substrate, the lower the fabrication cost per magnetic head. It is, therefore, proposed to separately fabricate the actual magnetic head portion (hereinafter called the magnetic head) and the flexible support member portion (hereinafter called the flexible support member), and subsequently to couple these members together so that the size of the magnetic heads can be reduced and the number of the magnetic heads obtained from one substrate can be increased.